Is There a Best Time to Exercise?
I love the New York Times. It's where I go first for my news. I like the global coverage; I like the recipes; I like the op-eds. I even like the crossword puzzles (Cmon, I know you do, too). But, as with every other news organization, the NYT is a for-profit company, and by definition, that means they're selling something. That something is news. To make money, they need you to read and click and read some more. And to get you to read and click and read some more, they need headlines that will get you to do just that. Don't get me wrong; I'm not singling out the NYT. Every news organization does this, as does every blogger and, well, everyone on the internet everywhere. It's their business. So, when I see headlines like, The Best Time of Day to Exercise or Can 4 Seconds of Exercise Make a Difference?, it gives me pause.
The first article suggests from its title that there IS a "best" time to exercise. Then I click and read. In this article, the author cites a single study that found that men with Type 2 diabetes who exercised in the afternoon improved their blood-sugar control better than those who exercised in the morning. So already, this may have nothing to do with me (or the majority of the population); I'm a woman who doesn't have T2D. Let's read further. The sample size? Just 11. The inclusion criteria? Men with type 2 diabetes who were 45-68 years of age and had a BMI between 23 and 33. Does that describe you? Maybe, but more likely not.
So, the problems I have are three-fold: First, the title is meant to sell the idea that there is a best time to exercise. There may be, and the findings of this study are interesting. But, these results apply to a very specific population. On top of this, there are only 11 study participants. I'd love to see a study with many more participants than that; chance goes down when study populations go up.
Second, one study, as I tell my students, does not mean it is fact. To be considered fact, this study's results would have to be supported over and over again with different types of studies and populations. (Let me just say, I DON'T think the NYT is irresponsible in publishing this story. But, I do think the reader should be aware that headlines are meant to sell news.)
And finally, here's how the author of the article closes out: "Ultimately...[the] most effective exercise regimen for each of us will align “with our daily routines” and exercise inclinations. Because exercise is good for us at any time of day — but only if we opt to keep doing it." So, ultimately, the author and I agree; exercise should be done when it fits into each person's life best. If it's at 6am, great. If it's at 6pm, great.
In a nutshell, it's okay to read these stories, as long as you read with a critical eye to see if it's actually relevant to your life. But mostly, ignore the big headlines until you see the same thing said over and over again by different scientists. And in the meantime, go for a walk anytime you want.